Light-emitting device and electronic apparatus

Abstract

The invention provides a light-emitting device and an electronic apparatus, which can improve light export efficiency. The light emitting device includes: a substrate; a first laminate having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a first light emitting layer provided between the first semiconductor layer and the second semiconductor layer; a first electrode provided between the substrate and the first laminate and electrically connected to the first semiconductor layer; a translucent second electrode which is provided on the opposite side of the first laminate from the substrate, has a first facing surface facing the substrate, and is electrically connected to the second semiconductor layer; a first insulating layer having a first portion provided on a side surface of the first laminate and a second portion provided on the first opposing surface and extending from the first portion along the first opposing surface; and a first metal layer disposed across the first portion and the second portion.

Description

Technical Field

[0001] The present invention relates to a light emitting device and an electronic device. Background Art

[0002] Light emitting elements such as LEDs (Light Emitting Diodes) are suitable for use as light sources for display devices and the like.

[0003] For example, Patent Document 1 describes a micro LED element, which includes: a nitride semiconductor layer, which is formed by stacking an N-type layer, a light-emitting layer, and a P-type layer in sequence as viewed from the light emitting surface side; a P-side electrode layer formed on the P-type layer; and an N-side electrode layer stacked on the light emitting surface.

[0004] Patent Document 1: International Publication No. 2019 / 038961

[0005] In the micro LED element as described above, it is desired to improve the light extraction efficiency. Summary of the invention

[0006] One embodiment of the light-emitting device of the present invention includes: a substrate; a first stack having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a first light-emitting layer arranged between the first semiconductor layer and the second semiconductor layer; a first electrode, which is arranged between the substrate and the first stack and is electrically connected to the first semiconductor layer; a light-transmitting second electrode, which is arranged on the side of the first stack opposite to the substrate, has a first opposing surface opposite to the substrate, and is electrically connected to the second semiconductor layer; a first insulating layer, which has a first portion arranged on a side surface of the first stack and a second portion arranged on the first opposing surface and extending from the first portion along the first opposing surface; and a first metal layer, which is arranged over the first portion and the second portion.

[0007] One embodiment of an electronic device according to the present invention includes one embodiment of the above-mentioned light emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a cross-sectional view schematically showing the light emitting device of this embodiment.

[0009] Figure 2 is a cross-sectional view schematically showing the light emitting device of this embodiment.

[0010] Figure 3 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0011] Figure 4It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0012] Figure 5 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0013] Figure 6 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0014] Figure 7 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0015] Figure 8 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0016] Fig. 9 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0017] Fig.10 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device of this embodiment.

[0018] Fig.11 It is a diagram schematically showing a projector according to this embodiment.

[0019] Fig.12 It is a top view schematically showing the display according to this embodiment.

[0020] Fig.13 It is a cross-sectional view schematically showing the display according to this embodiment.

[0021] Fig.14 : is a perspective view schematically showing the head mounted display according to the present embodiment.

[0022] Fig.15 It is a diagram schematically showing an image forming device and a light guiding device of the head mounted display according to the present embodiment.

[0023] Description of symbols

[0024] 2: light-emitting element; 2a: first light-emitting element; 2b: second light-emitting element; 10: substrate; 12: pad; 14: first layer; 16: second layer; 17: growth substrate; 18: support substrate; 19: buffer layer; 20: laminate; 20a: tapered portion; 21: side surface; 22: p-type semiconductor layer; 24: light-emitting layer; 26: n-type semiconductor layer; 27: contact surface; 28: convex portion; 30: p-electrode; 31: lower surface; 32: n-electrode; 34 : Opposing surface; 40: Insulating layer; 42: First extension; 44: Second extension; 46: Third extension; 48: First contact hole; 50: Lower metal layer; 60: Protective layer; 62: Second contact hole; 70: Upper metal layer; 72: Adhesive layer; 74: Reflecting surface; 80: Translucent component; 82: Emission surface; 90: Anti-etching layer; 100: Light-emitting device; 100R: Red light source; 100G: Green light source; 100B: Blue light source; 70 0: projector; 702R: first optical element; 702G: second optical element; 702B: third optical element; 704R: first light modulator; 704G: second light modulator; 704B: third light modulator; 706: cross-color prism; 708: projection device; 710: screen; 800: display; 810: drive circuit; 812: display area; 814: data line drive circuit; 816: scan line drive circuit; 81 8: control circuit; 820: lens array; 830: heat sink; 900: head-mounted display; 910a: first display unit; 910b: second display unit; 911: image forming device; 912: external component; 913: light modulation device; 914: projection device; 915: light guiding device; 916: image light guiding component; 917: reflection layer; 918: perspective component; 920: frame; 930a: first temple; 930b: second temple. DETAILED DESCRIPTION

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail using the accompanying drawings. In addition, the embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, the structures described below may not all be essential components of the present invention.

[0026] 1. Light-emitting device

[0027] 1.1. Structure

[0028] First, a light emitting device according to this embodiment will be described with reference to the drawings. Figure 1 1 is a perspective view schematically showing the light emitting device 100 according to the present embodiment.

[0029] like Figure 1As shown, the light emitting device 100 includes, for example, a substrate 10, a laminate 20, a p-electrode 30, an n-electrode 32, an insulating layer 40, a lower metal layer 50, a protective layer 60, an upper metal layer 70, and a light-transmitting member 80. The laminate 20, the p-electrode 30, the n-electrode 32, the insulating layer 40, and the lower metal layer 50 constitute a light emitting element 2. The light emitting element 2 is, for example, an LED.

[0030] The substrate 10 is, for example, a silicon substrate. A pad 12 is provided on the substrate 10. The pad 12 includes, for example, a first layer 14 and a second layer 16. The first layer 14 is provided on the substrate 10. For example, the first layer 14 is a layer formed by stacking a Ti layer and a Pt layer in this order from the substrate 10 side. The second layer 16 is provided on the first layer 14. For example, the second layer 16 is an Au layer.

[0031] A driving circuit for driving the light-emitting element 2 may also be provided on the substrate 10. The light-emitting element 2 is mounted on the substrate 10 via the pad 12. The light-emitting element 2 is, for example, mounted with the junction downward. For example, a plurality of light-emitting elements 2 are provided. Observed from the stacking direction of the p-type semiconductor layer 22 and the light-emitting layer 24 of the stack 20 (hereinafter, also referred to as the "stacking direction"), the plurality of light-emitting elements 2 may be arranged in a matrix. In the example shown in the figure, as the light-emitting element 2, a first light-emitting element 2a and a second light-emitting element 2b are provided. A plurality of pads 12 are provided corresponding to the plurality of light-emitting elements 2.

[0032] The stacked body 20 is provided between the p-electrode 30 and the n-electrode 32. Figure 2 The diagram shows the vicinity of the stacked body 20. Figure 1 A magnified image of Figure 2 As shown, the stack 20 has a tapered portion 20a having a tapered shape whose width increases as it approaches from the p-electrode 30 side to the n-electrode 32 side. The width of the tapered portion 20a gradually increases as it approaches from the p-electrode 30 side to the n-electrode 32 side. In the example shown in the figure, the shape of the tapered portion 20a is a trapezoid. In addition, the width refers to the size in the direction perpendicular to the stacking direction. The side surface 21 of the tapered portion 20a is inclined relative to the stacking direction. The side surface 21 of the tapered portion 20a constitutes the side surface of the stack 20.

[0033] The stacked body 20 includes a p-type semiconductor layer 22, a light emitting layer 24, and an n-type semiconductor layer 26. The p-type semiconductor layer 22, the light emitting layer 24, and the n-type semiconductor layer 26 constitute a tapered portion 20a. The p-type semiconductor layer 22, the light emitting layer 24, and the n-type semiconductor layer 26 are, for example, group III nitride semiconductors having a wurtzite crystal structure.

[0034] The p-type semiconductor layer 22 is provided on the p-electrode 30. The p-type semiconductor layer 22 is provided between the p-electrode 30 and the light emitting layer 24. The p-type semiconductor layer 22 has a first conductivity type. The p-type semiconductor layer 22 is, for example, a p-type GaN layer doped with Mg.

[0035] The light emitting layer 24 is disposed on the p-type semiconductor layer 22. The light emitting layer 24 is disposed between the p-type semiconductor layer 22 and the n-type semiconductor layer 26. The light emitting layer 24 has an i-type conductivity type that is not intentionally doped with impurities. The light emitting layer 24 generates light by injecting current. The light emitting layer 24 has, for example, a well layer and a barrier layer. The well layer and the barrier layer are i-type semiconductor layers. The well layer is, for example, an InGaN layer. The barrier layer is, for example, a GaN layer. The light emitting layer 24 has an MQW (Multiple Quantum Well: multiple quantum well) structure consisting of a well layer and a barrier layer.

[0036] The number of well layers and barrier layers constituting the light emitting layer 24 is not particularly limited. For example, only one well layer may be provided, in which case the light emitting layer 24 has an SQW (Single Quantum Well) structure.

[0037] The n-type semiconductor layer 26 is provided on the light emitting layer 24. The n-type semiconductor layer 26 is provided between the light emitting layer 24 and the n-electrode 32. In the example shown in the figure, the size of the n-type semiconductor layer 26 in the stacking direction is larger than the size of the p-type semiconductor layer 22 in the stacking direction. The n-type semiconductor layer 26 has a second conductivity type different from the first conductivity type. The n-type semiconductor layer 26 is, for example, an n-type GaN layer doped with Si.

[0038] The n-type semiconductor layer 26 has a contact surface 27 in contact with the n-electrode 32. A plurality of protrusions 28 are provided on the contact surface 27. The plurality of protrusions 28 are provided, for example, periodically. The height of the protrusions 28 is, for example, greater than 400 nm. The interval between the tops of adjacent protrusions 28 is, for example, less than 230 nm. The plurality of protrusions 28 may also constitute a moth-eye structure. In the illustrated example, the stack 20 is composed of a conical portion 20a and a plurality of protrusions 28. Through the plurality of protrusions 28, the change in the refractive index at the interface between the n-type semiconductor layer 26 and the n-electrode 32 can be smoothed in the direction from the n-type semiconductor layer 26 toward the n-electrode 32. Thus, the light reflected at the interface between the n-type semiconductor layer 26 and the n-electrode 32 can be reduced. In addition, although not illustrated, the plurality of protrusions 28 may also be provided randomly.

[0039] In the light emitting device 100, a pin diode is formed by the p-type semiconductor layer 22, the i-type light emitting layer 24, and the n-type semiconductor layer 26. In the light emitting device 100, when a forward bias voltage of the pin diode is applied between the p-electrode 30 and the n-electrode 32, current is injected into the light emitting layer 24 to cause recombination of electrons and holes in the light emitting layer 24. Through this recombination, the light emitting layer 24 generates light.

[0040] The p-electrode 30 is provided between the substrate 10 and the p-type semiconductor layer 22. The p-electrode 30 is electrically connected to the p-type semiconductor layer 22. The p-type semiconductor layer 22 may be in ohmic contact with the p-electrode 30. As the p-electrode 30, for example, an electrode in which a Pd layer, a Pt layer, and an Au layer are stacked in this order from the p-type semiconductor layer 22 side is used. The p-electrode 30 reflects light generated by the light-emitting layer 24 toward the n-electrode 32 side.

[0041] The p-electrode 30 is an electrode for injecting current into the light emitting layer 24. For example, a potential of a data signal is applied to the p-electrode 30. In the plurality of light emitting elements 2, the p-electrodes 30 are separated from each other, for example.

[0042] The n-electrode 32 is provided on the side of the stack 20 opposite to the substrate 10. The n-electrode 32 is provided on the n-type semiconductor layer 26. The n-electrode 32 is provided between the n-type semiconductor layer 26 and the light-transmitting member 80. The n-electrode 32 is arranged opposite to the substrate 10. The n-electrode 32 has an opposing surface 34 opposing the substrate 10. In the illustrated example, the opposing surface 34 is the lower surface of the n-electrode 32. The n-electrode 32 is electrically connected to the n-type semiconductor layer 26. The n-type semiconductor layer 26 can be in ohmic contact with the n-electrode 32. The n-electrode 32 is light-transmitting. Specifically, the n-electrode 32 allows the light generated by the light-emitting layer 24 to pass through. The light generated by the light-emitting layer 24 is emitted from the n-electrode 32 side. The material of the n-electrode 32 is, for example, ITO (Indium Tin Oxide).

[0043] The n-electrode 32 is another electrode for injecting current into the light-emitting layer 24. A constant potential is applied to the n-electrode 32, for example. A ground potential may also be applied to the n-electrode 32. In the plurality of light-emitting elements 2, the n-electrode 32 is, for example, a common electrode. Figure 1 In the example shown, the n-electrode 32 of the first light-emitting element 2 a and the n-electrode 32 of the second light-emitting element 2 b are continuously provided integrally.

[0044] The insulating layer 40 is provided to cover the stacked body 20. When viewed from the stacking direction, for example, the insulating layer 40 surrounds the stacked body 20. The insulating layer 40 has light-transmitting properties. Specifically, the insulating layer 40 allows the light generated by the light-emitting layer 24 to pass through. The insulating layer 40 is, for example, a SiO2 layer. Figure 2 As shown, the insulating layer 40 has, for example, a first extending portion 42 , a second extending portion 44 and a third extending portion 46 .

[0045] The first extension portion 42 of the insulating layer 40 is provided on the side surface 21 of the laminated body 20. The first extension portion 42 extends along the side surface 21. The first extension portion 42 covers the entire surface of the side surface 21, for example.

[0046] The second extension portion 44 of the insulating layer 40 is provided on the facing surface 34 of the n-electrode 32. In the example shown in the figure, the second extension portion 44 is provided on a portion of the facing surface 34 parallel to the upper surface of the substrate 10. The second extension portion 44 is connected to the first extension portion 42. The second extension portion 44 extends from the first extension portion 42 along the facing surface 34.

[0047] The third extension portion 46 of the insulating layer 40 is provided on the lower surface 31 of the p-electrode 30. The third extension portion 46 is connected to the first extension portion 42. The third extension portion 46 extends from the first extension portion 42 along the lower surface 31. The third extension portion 46 has a first contact hole 48 formed therein.

[0048] The lower metal layer 50 is provided over the first extension portion 42 and the second extension portion 44. In the example shown in the figure, the lower metal layer 50 is also provided over the third extension portion 46. The lower metal layer 50 is in contact with the extension portions 42, 44, 46.

[0049] The lower metal layer 50 is also provided in the first contact hole 48. The lower metal layer 50 is connected to the p-electrode 30. The lower metal layer 50 is also connected to the pad 12. The lower metal layer 50 can be eutectic bonded to the pad 12. The lower metal layer 50 can also be Au-Au bonded to the pad 12. The pad 12 is electrically connected to the p-electrode 30 via the lower metal layer 50. The lower metal layer 50 is, for example, an Au layer or an Al layer. The lower metal layer 50 reflects the light generated by the light emitting layer 24 toward the stacked body 20 side.

[0050] like Figure 1 As shown, the protective layer 60 is provided to cover the light emitting element 2. When viewed from the stacking direction, the protective layer 60 surrounds the stack 20. The protective layer 60 is provided between the first light emitting element 2a and the second light emitting element 2b. The protective layer 60 is provided between the substrate 10 and the p-electrode 30. In the example shown in the figure, the protective layer 60 is isolated from the substrate 10 via a gap. The protective layer 60 is, for example, a SiO2 layer. The protective layer 60 protects the light emitting element 2 from foreign matter and the like, and prevents the n-electrode 32 from being disconnected by contacting with the n-electrode 32 between the light emitting elements 2.

[0051] like Figure 2 As shown, a second contact hole 62 is formed on the protection layer 60. In the example shown in the figure, the second layer 16 of the pad 12 is disposed in the second contact hole 62.

[0052] like Figure 1As shown, the upper metal layer 70 is provided on the side of the n-electrode 32 opposite to the substrate 10. In the example shown in the figure, the upper metal layer 70 is provided on the n-electrode 32 via the adhesion layer 72. The adhesion layer 72 is, for example, a TiN layer. The adhesion layer 72 improves the adhesion between the n-electrode 32 and the upper metal layer 70. When viewed from the stacking direction, for example, the upper metal layer 70 does not overlap with the stacked body 20. The upper metal layer 70 is, for example, an Al layer.

[0053] The upper metal layer 70 has a reflecting surface 74. The reflecting surface 74 is a side surface of the upper metal layer 70. In the example shown in the figure, the reflecting surface 74 is located on the extension line of the side surface 21 of the tapered portion 20a. The inclination of the reflecting surface 74 with respect to the stacking direction is, for example, the same as the inclination of the side surface 21 with respect to the stacking direction. A plurality of reflecting surfaces 74 are provided corresponding to a plurality of light emitting elements 2. The reflecting surface 74 reflects the light generated by the light emitting layer 24 toward the light-transmitting member 80 side.

[0054] The light-transmitting member 80 is provided on the side of the n-electrode 32 opposite to the substrate 10. The light-transmitting member 80 is provided on the n-electrode 32. The light-transmitting member 80 is in contact with the reflecting surface 74 of the upper metal layer 70. When viewed from the stacking direction, for example, the upper metal layer 70 surrounds the light-transmitting member 80. The material of the light-transmitting member 80 is, for example, SiON. The light-transmitting member 80 transmits light that has transmitted through the n-electrode 32. The light-transmitting member 80 transmits light reflected by the reflecting surface 74.

[0055] The light-transmitting component 80 has an emission surface 82 for emitting light generated by the light-emitting layer 24. The emission surface 82 is the surface of the light-transmitting component 80 on the opposite side of the substrate 10. The emission surface 82 is, for example, a curved surface. In the example shown in the figure, the emission surface 82 is a convex surface. A plurality of light-transmitting components 80 are provided corresponding to a plurality of light-emitting elements 2. In the example shown in the figure, adjacent light-transmitting components 80 are provided continuously and integrally with each other. A plurality of light-transmitting components 80, for example, constitute a microlens array.

[0056] 1.2. Effects

[0057] In the light emitting device 100, the first light emitting element 2a includes a stacked body 20 as a first stacked body, the stacked body 20 having a p-type semiconductor layer 22 as a first semiconductor layer, an n-type semiconductor layer 26 as a second semiconductor layer, and a light emitting layer 24 as a first light emitting layer. The first light emitting element 2a further includes a p-electrode 30 as a first electrode provided between the substrate 10 and the stacked body 20 and electrically connected to the p-type semiconductor layer 22. The first light emitting element 2a further includes a light-transmitting n-electrode 32 as a second electrode, the n-electrode 32 being provided on the side of the stacked body 20 opposite to the substrate 10, having an opposing surface 34 as a first opposing surface opposed to the substrate 10, and the n-electrode 32 being electrically connected to the n-type semiconductor layer 26. The first light emitting element 2a further includes an insulating layer 40 as a first insulating layer, the insulating layer 40 having a first extension portion 42 as a first portion provided on the side surface 21 of the stacked body 20, and a second extension portion 44 as a second portion provided on the opposing surface 34 and extending from the first extension portion 42 along the opposing surface 34. The first light emitting element 2 a further includes a lower metal layer 50 as a first metal layer provided over the first extension portion 42 and the second extension portion 44 .

[0058] Therefore, in the light emitting device 100, for example, compared with the case where the lower metal layer is not provided throughout the first extension portion and the second extension portion of the insulating layer but is provided only on a portion of the first extension portion, the light generated by the light emitting layer 24 can be further reflected toward the stacked body 20 by the lower metal layer 50. Thus, the light extraction efficiency can be improved.

[0059] In the light emitting device 100, the lower metal layer 50 is connected to the p-electrode 30. Therefore, in the light emitting device 100, for example, miniaturization can be achieved compared to the case where the lower metal layer is separated from the p-electrode. In the case where the lower metal layer is separated from the p-electrode, it is necessary to consider the misalignment between the two during design, which makes it difficult to achieve miniaturization.

[0060] In the light emitting device 100, the second light emitting element 2b includes a stacked body 20 as a second stacked body, the stacked body 20 having a p-type semiconductor layer 22 as a third semiconductor layer, an n-type semiconductor layer 26 as a fourth semiconductor layer, and a light emitting layer 24 as a second light emitting layer. The second light emitting element 2b further includes a p-electrode 30 as a third electrode provided between the substrate 10 and the stacked body 20 and electrically connected to the p-type semiconductor layer 22. The second light emitting element 2b further includes a light-transmitting n-electrode 32 as a fourth electrode, the n-electrode 32 being provided on the side of the stacked body 20 opposite to the substrate 10, having an opposing surface 34 as a second opposing surface opposed to the substrate 10, and the n-electrode 32 being electrically connected to the n-type semiconductor layer 26. The second light emitting element 2b further includes an insulating layer 40 as a second insulating layer, the insulating layer 40 having a first extension portion 42 as a third portion provided on the side surface 21 of the stacked body 20, and a second extension portion 44 as a fourth portion provided on the opposing surface 34 and extending from the first extension portion 42 along the opposing surface 34. The second light emitting element 2b further includes a lower metal layer 50 as a second metal layer provided over the first extension portion 42 and the second extension portion 44. Therefore, in the light emitting device 100, the lower metal layer 50 can reduce crosstalk between the first light emitting element 2a and the second light emitting element 2b.

[0061] In the light emitting device 100, the p-electrode 30 of the first light emitting element 2a and the p-electrode 30 of the second light emitting element 2b are continuously provided integrally. Therefore, in the light emitting device 100, the p-electrode 30 can be used as a common electrode in the first light emitting element 2a and the second light emitting element 2b.

[0062] In the light emitting device 100 , the stacked body 20 has the tapered portion 20 a whose width increases from the p-electrode 30 side toward the n-electrode 32 side. Therefore, in the light emitting device 100 , the light generated by the light emitting layer 24 can be reflected toward the n-electrode 32 side at the side surface 21 .

[0063] The light emitting device 100 includes an upper metal layer 70 as a third metal layer, which is provided on the side of the n-electrode 32 opposite to the substrate 10 and has a reflection surface 74 for reflecting light generated by the light emitting layer 24, and the reflection surface 74 is located on the extension line of the side surface 21 of the tapered portion 20a. Therefore, in the light emitting device 100, it is possible to suppress the light transmitted through the n-electrode 32 from leaking to the outside, and emit light with a narrower radiation angle.

[0064] The light emitting device 100 includes a light transmissive member 80 disposed on the side of the n-electrode 32 opposite to the substrate 10 and in contact with the reflective surface 74. Therefore, the light emitting device 100 can more reliably reflect light that passes through the light transmissive member 80 and enters the reflective surface 74 toward the light transmissive member 80.

[0065] In the light emitting device 100 , the emission surface 82 of the light transmissive member 80 on the opposite side to the substrate 10 is a curved surface. Therefore, in the light emitting device 100 , the light transmissive member 80 can function as a lens.

[0066] In the light emitting device 100 , the insulating layer 40 is light-transmissive. In the light emitting device 100 , even if light generated by the light emitting layer 24 passes through the light-transmissive insulating layer 40 , the light passing through the insulating layer 40 can be reflected toward the laminate 20 by the lower metal layer 50 .

[0067] In addition, in the above description, the semiconductor layer provided between the substrate 10 and the light emitting layer 24 is a p-type semiconductor layer, and the semiconductor layer provided on the side of the light emitting layer 24 opposite to the substrate 10 is an n-type semiconductor layer, but the p-type and n-type may be reversed. That is, the semiconductor layer provided between the substrate 10 and the light emitting layer 24 may be an n-type semiconductor layer, and the semiconductor layer provided on the side of the light emitting layer 24 opposite to the substrate 10 may be a p-type semiconductor layer. In this case, the electrode electrically connected to the semiconductor layer provided between the substrate 10 and the light emitting layer 24 becomes an n-electrode, and the electrode electrically connected to the semiconductor layer provided on the side of the light emitting layer 24 opposite to the substrate 10 becomes a p-electrode.

[0068] In addition, in the above, an example in which a gap exists between the substrate 10 and the protective layer 60 is described, but the substrate 10 and the protective layer 60 may be in contact with each other. In this case, the pad 12 may be embedded in the substrate 10. The pad 12 and the light emitting element 2 may also be connected to each other by hybrid bonding.

[0069] In addition, although an example in which the lower metal layer 50 is provided in the first contact hole 48 is described above, the pad 12 may be provided in the first contact hole 48 instead of the lower metal layer 50 as long as the pad 12 is electrically connected to the p-electrode 30 .

[0070] In the above description, the light emitting layer 24 of the InGaN system is described, but various material systems that can emit light by injecting current can be used as the light emitting layer 24 according to the wavelength of the emitted light. For example, semiconductor materials such as AlGaN system, AlGaAs system, InGaAs system, InGaAsP system, InP system, GaP system, and AlGaP system can be used.

[0071] 2. Method for manufacturing a light-emitting device

[0072] Next, a method for manufacturing the light emitting device 100 according to the present embodiment will be described with reference to the drawings. Figures 3 to 10 It is a cross-sectional view schematically showing the manufacturing process of the light emitting device 100 according to the present embodiment.

[0073] like Figure 3 As shown, an n-type semiconductor layer 26, a light-emitting layer 24, and a p-type semiconductor layer 22 are epitaxially grown in sequence on a growth substrate 17. Examples of epitaxial growth methods include MOCVD (Metal Organic Chemical Vapor Deposition) and MBE (Molecular Beam Epitaxy). Through this process, a stack 20 is formed. The growth substrate 17 is a substrate for epitaxially growing the stack 20. The growth substrate 17 includes, for example, a supporting substrate 18 and a buffer layer 19 disposed on the supporting substrate 18. The supporting substrate 18 is, for example, a silicon substrate. The buffer layer 19 is, for example, a GaN layer.

[0074] Next, the p-electrode 30 is formed on the laminated body 20. The p-electrode 30 is formed by, for example, vacuum deposition, sputtering, or CVD (Chemical Vapor Deposition).

[0075] Next, the p-electrode 30 and the stacked body 20 are patterned. The patterning is performed so that the side surface 21 of the tapered portion 20a of the stacked body 20 is inclined relative to the stacking direction. The patterning is performed, for example, by photolithography and dry etching. By patterning the p-electrode 30 and the stacked body 20 together, the manufacturing process of the light-emitting device 100 can be shortened.

[0076] Next, the insulating layer 40 is formed on the laminated body 20 and the buffer layer 19. The insulating layer 40 is formed by, for example, the CVD method or the ALD method.

[0077] Next, the insulating layer 40 is patterned to form the first contact hole 48. This exposes the p-electrode 30. The patterning is performed by, for example, photolithography and etching.

[0078] like Figure 4 As shown, a lower metal layer 50 is formed on the p-electrode 30 and the insulating layer 40. The lower metal layer 50 is formed by, for example, vacuum deposition or sputtering.

[0079] like Figure 5 As shown, a resist layer 90 having a predetermined shape is formed so as to cover the laminated body 20. The resist layer 90 is formed by coating, exposure, and development.

[0080] like Figure 6 As shown, the lower metal layer 50 and the insulating layer 40 are dry-etched using the resist layer 90 as a mask. Thus, the buffer layer 19 is exposed. Here, the buffer layer 19 may be exposed without completely dry-etching the insulating layer 40.

[0081] like Figure 7As shown, the resist layer 90 is removed. The method of removing the resist layer 90 is not particularly limited.

[0082] like Figure 8 As shown, a protective layer 60 is formed so as to cover the laminated body 20. The protective layer 60 is formed by, for example, a CVD method or a spin coating method, and is planarized using a CMP (Chemical Mechanical Polishing) device or the like.

[0083] Next, the protective layer 60 is patterned to form the second contact hole 62. Thus, the lower metal layer 50 is exposed. The patterning is performed by, for example, photolithography and etching.

[0084] like Fig. 9 As shown, the lower metal layer 50 is bonded to the pad 12. Examples of the bonding method include eutectic bonding and Au-Au bonding. Alternatively, the two may be bonded using solder or the like.

[0085] like Fig.10 As shown, the growth substrate 17 is removed. The growth substrate 17 is removed by, for example, etching, CMP, etc. As a result, the n-type semiconductor layer 26 is exposed.

[0086] Next, the n-type semiconductor layer 26 is patterned to form a plurality of protrusions 28. The patterning is performed by, for example, photolithography and etching.

[0087] like Figure 1 As shown, an n-electrode 32 is formed on the n-type semiconductor layer 26. The n-electrode 32 is formed by, for example, vacuum deposition or sputtering.

[0088] Next, the upper metal layer 70 is formed on the n-electrode 32 via the adhesion layer 72. The upper metal layer 70 and the adhesion layer 72 are formed by, for example, sputtering, CVD, vacuum deposition, or electroplating.

[0089] Next, the light-transmitting member 80 is formed on the n-electrode 32. The light-transmitting member 80 is formed by, for example, the CVD method.

[0090] Next, the light-transmitting member 80 is patterned to form the curved emission surface 82. The patterning is performed by, for example, photolithography and etching.

[0091] Through the above steps, the light emitting device 100 can be manufactured.

[0092] 3. Projector

[0093] Next, a projector as an electronic device according to the present embodiment will be described with reference to the drawings. Fig.11 Schematic diagram of a projector 700 according to this embodiment.

[0094] The projector 700 includes, for example, a light emitting device 100 as a light source.

[0095] The projector 700 includes a housing (not shown) and a red light source 100R, a green light source 100G, and a blue light source 100B disposed in the housing and emitting red light, green light, and blue light, respectively. Fig.11 , a red light source 100R, a green light source 100G, and a blue light source 100B are shown in a simplified manner.

[0096] The projector 700 further includes, for example, a first optical element 702R, a second optical element 702G, a third optical element 702B, a first light modulator 704R, a second light modulator 704G, a third light modulator 704B, and a projection device 708, which are arranged in a housing. The first light modulator 704R, the second light modulator 704G, and the third light modulator 704B are, for example, transmissive liquid crystal light valves. The projection device 708 is, for example, a transmissive lens.

[0097] The light emitted from the red light source 100R enters the first optical element 702R. The light emitted from the red light source 100R is condensed by the first optical element 702R. In addition, the first optical element 702R may have functions other than condensing. The second optical element 702G and the third optical element 702B may also have functions other than condensing.

[0098] The light focused by the first optical element 702R is incident on the first light modulator 704R. The first light modulator 704R modulates the incident light according to the image information. Then, the projection device 708 magnifies the image formed by the first light modulator 704R and projects it onto the screen 710.

[0099] The light emitted from the green light source 100G enters the second optical element 702G. The light emitted from the green light source 100G is condensed by the second optical element 702G.

[0100] The light focused by the second optical element 702G is incident on the second light modulator 704G. The second light modulator 704G modulates the incident light according to the image information. Then, the projection device 708 magnifies the image formed by the second light modulator 704G and projects it onto the screen 710.

[0101] The light emitted from the blue light source 100B enters the third optical element 702B. The light emitted from the blue light source 100B is condensed by the third optical element 702B.

[0102] The light focused by the third optical element 702B is incident on the third light modulator 704B. The third light modulator 704B modulates the incident light according to the image information. Then, the projection device 708 magnifies the image formed by the third light modulator 704B and projects it onto the screen 710.

[0103] The projector 700 further includes, for example, a cross dichroic prism 706 that combines the light emitted from the first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B and guides the combined light to a projection device 708 .

[0104] The three color lights modulated by the first light modulator 704R, the second light modulator 704G and the third light modulator 704B are incident on the cross dichroic prism 706. The cross dichroic prism 706 is formed by bonding four right-angle prisms, and a dielectric multilayer film reflecting red light and a dielectric multilayer film reflecting blue light are arranged on its inner surface. The three color lights are synthesized by these dielectric multilayer films to form light representing a color image. Then, the synthesized light is projected onto the screen 710 by the projection device 708 to display the enlarged image.

[0105] In addition, the red light source 100R, the green light source 100G, and the blue light source 100B may also use the light emitting device 100 as a pixel of an image and control it according to image information, thereby directly forming an image without using the first light modulator 704R, the second light modulator 704G, and the third light modulator 704B. Furthermore, the projection device 708 may also enlarge the image formed by the red light source 100R, the green light source 100G, and the blue light source 100B and project it onto the screen 710.

[0106] In the above example, a transmissive liquid crystal light valve is used as the light modulator, but a light valve other than liquid crystal can also be used, and a reflective light valve can also be used. Examples of such light valves include reflective liquid crystal light valves and digital micro mirror devices. The structure of the projection device is appropriately changed according to the type of light valve used.

[0107] Furthermore, the light source can also be applied to a light source device of a scanning type image display device having a scanning unit which is an image forming device that displays an image of a desired size on a display surface by scanning light from a light source on a screen.

[0108] 4. Display

[0109] Next, a display as an electronic device according to the present embodiment will be described with reference to the drawings. Fig.12 1 is a plan view schematically showing a display 800 according to the present embodiment. Fig.13is a cross-sectional view schematically showing a display 800 according to this embodiment. Fig.12 In FIG. 1 , the X-axis and the Y-axis are shown as two axes perpendicular to each other. Fig.12 and Fig.13 In FIG. 1 , the light emitting device 100 is shown in a simplified manner.

[0110] The display 800 has, for example, a light emitting device 100 as a light source.

[0111] The display 800 is a display device for displaying images. The images include images that display only character information. The display 800 is a self-luminous display. Fig.12 and Fig.13 As shown, the display 800 has, for example, a driving circuit 810 , a lens array 820 , and a heat sink 830 .

[0112] The driving circuit 810 is provided on the substrate 10. The driving circuit 810 drives the light emitting element 2 based on input image information, for example. The substrate 10 has, for example, a display area 812. The driving circuit 810 has a data line driving circuit 814, a scanning line driving circuit 816, and a control circuit 818.

[0113] The display area 812 is composed of a plurality of pixels P. In the example shown in the figure, the pixels P are arranged along the X-axis and the Y-axis.

[0114] Although not shown, a plurality of scan lines and a plurality of data lines are provided on the substrate 10. For example, the scan lines extend along the X axis, and the data lines extend along the Y axis. The scan lines are connected to the scan line driving circuit 816. The data lines are connected to the data line driving circuit 814. Pixels P are provided corresponding to the intersections of the scan lines and the data lines.

[0115] One pixel P has, for example, one light emitting element 2, one light-transmitting member 80, and a pixel circuit (not shown). The pixel circuit has a switching transistor that functions as a switch of the pixel P. The switching transistor has a gate connected to a scanning line and one of a source and a drain connected to a data line.

[0116] The data line driving circuit 814 and the scanning line driving circuit 816 are circuits for controlling the driving of the light emitting element 2 constituting the pixel P. The control circuit 818 controls the display of an image.

[0117] The image data is supplied from the upper circuit to the control circuit 818. The control circuit 818 supplies various signals based on the image data to the data line drive circuit 814 and the scanning line drive circuit 816.

[0118] When the scanning line driving circuit 816 enables the scanning signal to select the scanning line, the switching transistor of the selected pixel P is turned on. At this time, the data line driving circuit 814 supplies the data signal from the data line to the selected pixel P, so that the light emitting element 2 of the selected pixel P emits light according to the data signal.

[0119] The lens array 820 is composed of a plurality of light-transmitting members 80. The heat sink 830 is in contact with the substrate 10. The heat sink 830 is made of a metal such as copper or aluminum. The heat sink 830 dissipates heat generated by the light-emitting element 2.

[0120] 5. Head-mounted displays

[0121] 5.1. Overall structure

[0122] Next, a head mounted display as an electronic device according to the present embodiment will be described with reference to the drawings. Fig.14 1 is a perspective view schematically showing a head mounted display 900 according to the present embodiment.

[0123] like Fig.14 As shown, the head-mounted display 900 is a head-mounted display having an appearance like glasses. The head-mounted display 900 is worn on the head of the observer. The observer refers to a user who uses the head-mounted display 900. The head-mounted display 900 enables the observer to visually see the image light based on the virtual image and to visually see the external image in a transparent manner.

[0124] The head mounted display 900 includes, for example, a first display portion 910 a , a second display portion 910 b , a frame 920 , a first temple 930 a , and a second temple 930 b .

[0125] The first display unit 910a and the second display unit 910b display images. Specifically, the first display unit 910a displays a virtual image for the right eye of the observer. The second display unit 910b displays a virtual image for the left eye of the observer. The display units 910a and 910b include, for example, an image forming device 911 and a light guide device 915.

[0126] The image forming device 911 forms image light. The image forming device 911 includes, for example, an optical system such as a light source and a projection device, and an external component 912. The external component 912 houses the light source and the projection device.

[0127] The light guide device 915 covers the viewer's eyes. The light guide device 915 guides the image light formed by the image forming device 911, and overlaps the external light and the image light for the viewer to see. The image forming device 911 and the light guide device 915 will be described in detail later.

[0128] The frame 920 supports the first display unit 910a and the second display unit 910b. The frame 920 surrounds the display units 910a and 910b, for example. In the example shown in the figure, the image forming device 911 of the first display unit 910a is attached to one end of the frame 920. The image forming device 911 of the second display unit 910b is attached to the other end of the frame 920.

[0129] A first temple 930a and a second temple 930b extend from the frame 920. In the illustrated example, the first temple 930a extends from one end of the frame 920. The second temple 930b extends from the other end of the frame 920.

[0130] When the head mounted display 900 is worn by an observer, the first temple 930a and the second temple 930b are suspended from the observer's ears, and the observer's head is located between the temples 930a and 930b.

[0131] 5.2. Image forming device and light guiding device

[0132] Fig.15 Schematically shows an image forming device 911 and a light guide device 915 of a first display unit 910a of a head mounted display 900. The first display unit 910a and the second display unit 910b have substantially the same structure. Therefore, the following description of the first display unit 910a can be applied to the second display unit 910b.

[0133] like Fig.15 As shown, the image forming device 911 includes, for example, a light emitting device 100 as a light source, a light modulation device 913, and a projection device 914 for imaging.

[0134] The light modulator 913 modulates the light incident from the light emitting device 100 according to the image information and emits image light. The light modulator 913 is a transmissive liquid crystal light valve. Alternatively, the light emitting device 100 may be a self-luminous light emitting device that emits light according to the input image information. In this case, the light modulator 913 is not provided.

[0135] The projection device 914 projects the image light emitted from the light modulator 913 toward the light guide device 915. The projection device 914 is, for example, a transmission lens. As a lens constituting the projection device 914, a lens having an axially symmetric surface as a lens surface may be used.

[0136] The light guide device 915 is, for example, screwed to the lens barrel of the projection device 914 to be positioned with high accuracy relative to the projection device 914. The light guide device 915 includes, for example, an image light guide member 916 for guiding image light and a see-through member 918 for see-through.

[0137] The image light emitted from the projection device 914 is incident on the image light guide component 916. The image light guide component 916 is a prism that guides the image light toward the eyes of the observer. The image light incident on the image light guide component 916 is repeatedly reflected on the inner surface of the image light guide component 916, and then reflected by the reflection layer 917 and emitted from the image light guide component 916. The image light emitted from the image light guide component 916 reaches the eyes of the observer. The reflection layer 917 is composed of, for example, a metal or a dielectric multilayer film. The reflection layer 917 can also be a half mirror.

[0138] The perspective component 918 is adjacent to the image light guide component 916. The perspective component 918 is fixed to the image light guide component 916. The outer surface of the perspective component 918 is, for example, continuous with the outer surface of the image light guide component 916. The perspective component 918 enables the observer to see through the external light. The image light guide component 916, in addition to the function of guiding the image light, also has the function of enabling the observer to see through the external light. In addition, the head mounted display 900 may also be a structure that does not enable the observer to see through the external light.

[0139] The light emitting device of the above embodiment can also be used in addition to projectors, displays, and head mounted displays. The light emitting device of the above embodiment is used, for example, for indoor and outdoor lighting, laser printers, scanners, sensor devices using light, EVF (Electronic View Finder), wearable displays such as smart watches, vehicle-mounted lights, and vehicle-mounted head-up displays.

[0140] The above-mentioned embodiment and modification examples are examples, and the present invention is not limited thereto. For example, each embodiment and each modification example may be appropriately combined.

[0141] The present invention includes structures that are substantially the same as the structures described in the embodiments, such as structures with the same functions, methods and results, or structures with the same purposes and effects. In addition, the present invention includes structures that replace non-essential parts of the structures described in the embodiments. In addition, the present invention includes structures that play the same role and effect as the structures described in the embodiments or structures that can achieve the same purpose. In addition, the present invention includes structures that add known technology to the structures described in the embodiments.

[0142] The following contents are derived from the above-mentioned embodiments and modifications.

[0143] One embodiment of a light-emitting device includes: a substrate; a first stack having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a first light-emitting layer arranged between the first semiconductor layer and the second semiconductor layer; a first electrode, which is arranged between the substrate and the first stack and is electrically connected to the first semiconductor layer; a light-transmitting second electrode, which is arranged on the side of the first stack opposite to the substrate, has a first opposing surface opposite to the substrate, and is electrically connected to the second semiconductor layer; a first insulating layer, which has a first portion arranged on a side surface of the first stack and a second portion arranged on the first opposing surface and extending from the first portion along the first opposing surface; and a first metal layer, which is arranged over the first portion and the second portion.

[0144] According to this light emitting device, the light extraction efficiency can be improved.

[0145] In one embodiment of the light emitting device, the first metal layer may be connected to the first electrode.

[0146] According to this light emitting device, miniaturization can be achieved.

[0147] In one embodiment of the light-emitting device, it may also include: a second stack having a third semiconductor layer of the first conductivity type, a fourth semiconductor layer of the second conductivity type, and a second light-emitting layer arranged between the third semiconductor layer and the fourth semiconductor layer; a third electrode, which is arranged between the substrate and the second stack and is electrically connected to the third semiconductor layer; a translucent fourth electrode, which is arranged on the side of the second stack opposite to the substrate, has a second opposing surface opposite to the substrate, and is electrically connected to the fourth semiconductor layer; a second insulating layer having a third portion arranged on the side of the second stack and a fourth portion arranged on the second opposing surface and extending from the third portion along the second opposing surface; and a second metal layer, which is arranged over the third portion and the fourth portion.

[0148] According to this light-emitting device, crosstalk between the first light-emitting element including the first stack, the first electrode, and the second electrode and the second light-emitting element including the second stack, the third electrode, and the fourth electrode can be reduced.

[0149] In one aspect of the light emitting device, the second electrode and the fourth electrode may be provided continuously and integrally.

[0150] According to this light-emitting device, the second electrode and the fourth electrode can be used as common electrodes in the first light-emitting element and the second light-emitting element.

[0151] In one aspect of the light emitting device, the first stack may include a tapered portion whose width increases from the first electrode side toward the second electrode side.

[0152] According to this light-emitting device, light generated by the first light-emitting layer can be reflected toward the second electrode side at the side surface of the stacked body.

[0153] In one embodiment of the light-emitting device, the light-emitting device may include a third metal layer, which is arranged on the side of the second electrode opposite to the substrate, and has a reflecting surface for reflecting light generated by the first light-emitting layer, and the reflecting surface is located on the extension line of the side surface of the cone.

[0154] According to this light emitting device, it is possible to suppress leakage of light transmitted through the second electrode to the outside and emit light with a narrower radiation angle.

[0155] In one aspect of the light emitting device, a light-transmitting member may be included. The light-transmitting member is provided on a side of the second electrode opposite to the substrate and is in contact with the reflecting surface.

[0156] According to this light emitting device, at the reflection surface, light that has passed through the light-transmitting member and entered the reflection surface can be more reliably reflected toward the light-transmitting member.

[0157] In one aspect of the light emitting device, a surface of the light transmissive member on the opposite side to the substrate may be a curved surface.

[0158] According to this light emitting device, the light-transmitting member can function as a lens.

[0159] In one embodiment of the light emitting device, the first insulating layer may be light-transmissive.

[0160] According to this light emitting device, even if light generated by the first light emitting layer passes through the light-transmitting first insulating layer, the light that has passed through the first insulating layer can be reflected toward the first stacked body by the first metal layer.

[0161] One embodiment of an electronic device includes one embodiment of the above-mentioned light emitting device.

Claims

1. A light emitting device, comprising: substrate; A first stacked body including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a first light emitting layer provided between the first semiconductor layer and the second semiconductor layer; A first electrode, which is disposed between the substrate and the first stacked body and is electrically connected to the first semiconductor layer; a light-transmitting second electrode, which is disposed on the side of the first stacked body opposite to the substrate, has a first facing surface facing the substrate, and is electrically connected to the second semiconductor layer; a first insulating layer having a first portion provided on a side surface of the first stack and a second portion provided on the first opposing surface and extending from the first portion along the first opposing surface; as well as A first metal layer is disposed throughout the first portion and the second portion.

2. The light emitting device according to claim 1, wherein: The first metal layer is connected to the first electrode.

3. The light emitting device according to claim 1, wherein: The light emitting device comprises: a second stacked body having a third semiconductor layer of the first conductivity type, a fourth semiconductor layer of the second conductivity type, and a second light emitting layer provided between the third semiconductor layer and the fourth semiconductor layer; a third electrode disposed between the substrate and the second stack and electrically connected to the third semiconductor layer; a light-transmitting fourth electrode, which is disposed on the side of the second stack opposite to the substrate, has a second facing surface facing the substrate, and is electrically connected to the fourth semiconductor layer; a second insulating layer having a third portion provided on a side surface of the second stacked body and a fourth portion provided on the second opposing surface and extending from the third portion along the second opposing surface; as well as A second metal layer is disposed over the third portion and the fourth portion.

4. The light emitting device according to claim 3, wherein: The second electrode is continuously and integrally provided with the fourth electrode.

5. The light emitting device according to claim 1, wherein: The first stacked body has a tapered portion whose width increases from the first electrode side toward the second electrode side.

6. The light emitting device according to claim 5, wherein: The light emitting device includes a third metal layer, which is disposed on a side of the second electrode opposite to the substrate and has a reflecting surface for reflecting light generated by the first light emitting layer. The reflecting surface is located on the extension line of the side surface of the tapered portion.

7. The light emitting device according to claim 6, wherein: The light emitting device includes a light-transmitting component, which is disposed on a side of the second electrode opposite to the substrate and in contact with the reflective surface.

8. The light emitting device according to claim 7, wherein: A surface of the light-transmitting member opposite to the substrate is a curved surface.

9. The light emitting device according to claim 1, wherein: The first insulating layer is light-transmissive.

10. An electronic device comprising the light emitting device according to any one of claims 1 to 9.

Images